Beam-compass.



J. F. ELLSWORTH. BEAM COMPASS.

APPLICATION :FILED MAR. 11, 1901.

l j,lI

l 1 I f l l 1 l m n 1 Witnesses No MODEL.

UNi'TnD STATES PATENT OFFCE.

JOHN F. ELLSWORTH, OF BUFFALO, NEW YORK, ASSIGNOR OF ONElIALF TO GEORGE T. CHESTER, OF BUFFALO, NEW YORK.

BEAM-COMPASS.

SPECIFIGATION forming part of Letters Patent N 0. 718,923, dated January 20, 1 903. Application led March 11,1901. Serial No. 50,646. (N mOdel-J To @ZZ whom t may concern.-

Beit known that I, JOHN F. ELLSWORTH, a citizen ot' the United States, and a resident of the city of Buffalo, in the count-y ot Erie and State of New York, haveinvented certain new and useful Improvements in Beam-Oompasses; and I do hereby declare that the following description, taken in connection with the accompanying sheet ot' drawings, forms 1o a full, clear, and exact specification, which will enable others skilled in the art to which it appertains to make and use the same.

This invention has general reference to improvements in telescopic beam-Compasses;

and it consists, essentially, in the novel and peculiar combination of parts and details of construction, as hereinafter first fully set forth and described and then pointed out in the claims.

2o In the drawings already mentioned, which serve to illustrate this invention more fully, Figure 1 is an elevation of my improved beam- Compasses. Fig. 2is a longitudinal sectional elevation of one end thereof, and Fig. 3 a

similar view of the opposite end of said beamcompasses. Fig. 4 is a sectional end elevation in line o; .fr of Fig. 3. Fig. 5 is an end elevation in line y y of Fig. 3.

Like parts are designated by corresponding 3o symbols of reference in all the figures.

The object of this invention is the production of a convenient telescopic beam-compass and the like.

1 in the drawings represents the main tube of my telescopic beam-Compasses. This tube has in its interior a plug 2, internally screwthreaded for the reception of an adjustingscrew 3, said plug being securely fastened in the main tube 1, a short distance from the end 4o thereof.

4 is ashort section of tubing snugly fitting over the main tube 1. It has on its end a cap 5, also centrally perforated for the passage of the said adjusting-screw 3, a milled thumb nut or button 6 being tted to the end ot the said screw and having a shouldered bearing against the cap.

7 is a spiral spring surrounding the adjust- :ing-screw 3 and bearing against the plug 2 5o and the cap 5, respectively, to force the tubular member 4 outwardly upon the main tube 1. To this tubular member 4 is attached the usual fixture 8, being the compass-point or a pen or pencil holder.

9 is an auxiliary tube snugly sliding within 55 the main tube 1. It also has its end capped by a cap 10 and its center perforated for the passage of a clamping-screw 11, passing centrally through the entire length of the auxiliary tube 9 and engaging a plug 12, having a 6o tapering portion or section 13 engaging the tapering internal bore of the auxiliary tube 9, which latter is slitted at 14, Fig. 5, to enable this end of the auxiliary tube to expand, and thereby lock itself in the main tube 1, a Wing 15 being provided on the plug 12, engaging one of the slits 14 to prevent it from rotating when the fastening-screw is revolved. The end of the fastening-screw 11 is provided with a button 16 to facilitate the rotating of 7o said screw.

Upon the auxiliary tube 9 is plaeda sleeve 17, preferably slitted longitudinally at 18, and upon this sleeve in turn is placed the usual compass-fixture 19, being a pen or pencil point or a needle-point of usual construction, this fixture, with its tube 20, iitting the short sleeve 17 snugly, so that when a clamping or thumb ,screw 21 is turned it will securely hold the fixture 19 in place and at the 8o same time clamp the sleeve 17 upon the auxiliary tube 9.

It will now be observed that the auxiliary tube sliding Within the main tube and forming, as it were, the beam of a pair of beam- Compasses enables the beam to be lengthened and shortened by sliding the auxiliary tube Within the main tube, while tine adjustment can be made by turning the button 6 upon the adj usting-screw 3 in the proper di. 9o rection. The exterior diameter of the sleeve 17 and the main tube l coincide, so that when it is desired to use a short beam only and to scribe curves of less radii than the length of the main beam the fixture 19 may be slid 95 from its sleeve 17 upon the main tube 1 and there fastened at any point or position by the before-mentioned thumb-screw 21.

This tubular telescopic beam for Compasses is very light and more conveniently handled too than the usual sectional ora full beam. It requires a shorter case to contain its various parts and when made of aluminium or aluminium alloys is lighter than any other beameompasses now in the market. It especially obviates the inconvenience of a long arm eX- tending beyond the pencil-point, which defeotis common to all other beam-Compasses When extended by an additional rigid arm or beam.

I-Iaving thus fully described this invention, I claim as new and desire to secure to me by Letters Patent of the United States- 1. In a tubular beam compass, a main tube, a point-carrying fixture upon said main tube, an auxiliary tube in vsaid main tube, means for looking said auxiliary tube in the main tube, a sleeve upon said auxiliary tube having an outside diameter equal to that of the main tube, and a pen and pencil carrying tubular fixture upon the said sleeve as and for the use and purpose specified.

2. A beam-compass oomprisinga main tube, a tubular sleeve sliding thereon, means for adjusting the sleeve With relation to the main tube, an auxiliary tube telescoping within the main tube, and means for looking said auxiliary tube to the main tube, said means being concealed Within the main tube and operable from the end of the auxiliary'tube.

3. A beam-compass eomprisinga main tube, a tubular sleeve sliding thereon, means for adjusting' the sleeve With relation to the main tube, an auxiliary tube telesooping within the main tube, the end of said auxiliary tube being slitted, and means for spreading said slitted end to lock the auxiliary tube to the main tube.

In testimony that I claim the foregoing as my invention I have hereunto set my hand, at Buffalo, New York, this 6th day of March, 1901, in the presence of two subscribing Witnesses.

JOHN F. ELLsWoRTH. 

